This invention relates to devices which generate electricity from a fluid flow. Specifically the present invention relates to generators which are used in conjunction with electrical bomb fuzes. More specifically, the present invention concerns generators which are normally inoperative, but which may become operative upon the occurrence of specific events.
Fuzes permit explosive devices to detonate under certain conditions and prohibit detonation under all other conditions. Safety of those work with explosive devices is a key concern in fuze technology. Accordingly, many fuze designs go to great lengths to prohibit undesirable detonations of the explosive devices. Many fuzes are electrically energized. Thus, electrically energized fuzes prohibit detonation unless the fuze is energized.
Bombs are typically delivered to their intended targets by being launched through a fluid, such as air or water. When these bombs employ electrically energized fuzes, safety is enhanced by using a generator to electrically energize the fuze. Motion of the bomb through the fluid causes the generator to generate electricity, which in turn energizes the fuze. Accordingly, the bomb must be in motion before it can become armed.
Additional schemes insure that the bomb does not become undesirably armed even when it is in motion, such as when the bomb is being carried by an aircraft. One scheme utilizes a pop-up cover over a generator which is contained within an enclosure. The enclosure is designed to remain closed until the bomb is delivered to its target. As long as the enclosure remains closed, the fluid through which the bomb is moving cannot engage the generator, the generator cannot generate electricity, the fuze does not become energized, and the bomb cannot detonate.
Prior art devices provide various enclosure schemes. However, these devices suffer significant problems. These devices tend to exhibit a high profile in that they excessively protrude beyond the exterior surface of the bomb. This high profile causes problems concerning mounting the bomb to the aircraft or other vehicle. In some situations the bomb cannot be mounted. In other situations the bomb can be mounted, but the bomb's mounting lugs must be unscrewed so that the lugs extend sufficiently above the generator enclosure to allow attachment. However, when the bomb lugs have been unscrewed a dangerous situation exists because the bombs cannot be securely attached to the vehicle.
Another problem with the prior art devices relates to the generator efficiency. These devices typically deflect the fluid stream down into the enclosure where the fluid flow then engages a generator. Much of the fluid's energy is lost in the deflection. Thus, the prior art devices use relatively large and expensive generators to compensate for the relatively low energy fluid flow.
Yet another problem of the prior art concerns the reliability of opening the enclosure. If a sliding sleeve technique is used to open the enclosure, the sleeve is subject to binding and the enclosure reliably opens only if the opening force is exerted in precisely the proper direction. Thus, prior art devices often fail to open when they should open.